When buying scrap gold there is nothing more painful than finding out later that what you bought was not real gold because you didn’t do a test on it. Testing gold should be a priority for all scrap buyers.
Although there is electronic testing equipment available, the less expensive route to take is the acid test. Test stones and acids can be purchased from any Jewelers supply store or through this site. (see right sidebar)
The “Test Stone” is similar to a knife sharpening stone. The acids are in small plastic bottles with a different acid for each karat grade (18k, 14k, 10k).
Testing Procedure
The following is the procedure for doing an acid test.
To test the item you simply rub it against the stone. Press firmly as you rub until you see the gold on the stone. Then, using the bottle of acid, squeeze a drop on the stone where you rubbed the gold.
If it disappears, or turns green, the item is not gold. If it stays unchanged it is gold. If it turns a dark brown it is a lower karat grade than the acid you are using.
If you already have an idea what karat grade the gold is, use the acid labeled that particular karat. If you’re unsure what karat it is, start with the 18k acid. If it turns dark brown then try it again with 14k acid. If it still turns dark brown it is most likely 10k.
If you have any doubts about the item being genuine, or if you think it may be gold plated, run the test several times. Sometimes the gold plating is very thick and will not disappear from the stone during the first test. What I do is rub the item on the stone several times to be sure to rub through the plating. Then I drop the acid on the stone where I did the last rub.
After you are finished testing, wipe the acid off of the stone with a wet cloth.
Be careful not to get the acid on your fingers it will leave a yellow stain deep into your skin and take weeks to wear off.
Once you’ve determined that the item is actually gold, it’s time to determine its value. The first step in that process is to calculate it’s gold weight.
